Producing ammonia.



UNITED STATES PATENT OFFICE.

FRITZ HABER, OF BERLIN, AND CARL BOSCH AND ALWIN MITTASCH. OF LUDWIGS- HAFEN-ON-THE-RHINE. GERMANY; ASSIGNORS TO BADISCHE ANILIN & SODA FABRIK, OF LUDWIGSHAFEN-ON-THE-RHINE, GERMANY. A CORPORATION.

PRQDUCI I NG AMMONIA.

No Drawing. Application filed January 30, 1912. SerialNo. 674,423.

To all who, 5 may (to/ (131711 In this application we wish to be under- Be it known that we, Farrz Hanna, CARL stood as including under the term tung- BOSCH, and ALwIX l\Irrr.\sc1r, subjects the stenlalso a compound, such as a nit-rid or first two of the King of Prussiaand the lat Jamid-nitrid, thereof, which is also capable tor of the King of Saxony, residing the first of exerting the required catalytic power,

at Berlin and the others at Ludwigshafen- 'sinceit isdiificult to ascertain when working Specification ofLettersPatent. p t t l 1915.

on-the-Rhine German have invented new whether the tun 'sten remains as metallic and useful Improvements in Producing Amtungsten, or whether and to what degree it monia, of which the following is a specimay be converted into such nitrid or simification. lar compound. a In the specification of French Patent No. Suitable temperatures for producing am- 430595 it is stated that small quantities of monia according to this invention lie beammonia can'be prepared synthetically by tween about l00 and 7 00 C; passing a mixture of nitrogen and hydro- The following examples will serve to illusgen over a catalytic agent consistin flof zinc, trate further the nature of our invention, and it is also suggested that, instead of zinc, which, however, is not confined to these extungsten can, less advantageously,i-"becinamples: ployed for the same purpose, as a higher. Example 1: Heat ammonium tungstate temperature is maintained. which is free from fixed alkali or tungsten \Ve have discovered that ammonia can oxychlorid, in an atmosphere of ammonia, be prepared using tungsten as a catalytic rapidly, to 800 0., and then place the mass agent provided a special new form of tungobtained in the contact tube and employ it sten be employed, and that, in this case, yields of ammonia can be obtained which while employing a pressure of about 150 for the production of ammonia at 600 C,

are far greater than those which can be produced when employing zinc or tungsten, as usually prepared, for the catalytic combination The tungsten for use as a catalytic agent according to our invention is proatmospheres.

Example 2: Fill pure tungstic acid into a contact tubeand pass a pure mixture of 3 parts of hydrogen and 1 part of nitrogen over it at a temperature of from 550 to duced as described in the specification of 600 C., and at a pressure of 150 atmosapplication for patent Serial No. 67 7 ,4=12, pheres. The tungstic acid is first of all rethat is to say, from pure compounds such duced to metallic tungsten or to a tungstenas the oxids, halogen compounds, or amnitrogen compound, whereupon the formamonium tungstate, by reduction at a modtion of ammonia immediately commences erate temperature with hydrogen or ammonia. W'Vhen employing hydrogen for the pound obtained by reduction with a gas conreduction, pressure should preferably be an taining nitrogen can be converted into the ployed and the temperature should not eX- metal by dissociation in oa ceed 600 6., while, with ammonia, the use of a temperature of about 800 C. appears a pressure of S0 atmospheres over pure tungto result quickly in the production of a. stic acid at a temperature of from 550 tungsten Which gives practically as good to 600 C. The reduction takes place very yields --as does that produced with hydrorapidly. Then place the mass in the congen ,or ammonia at about 600 O. If de- I tact tube and pass a current of nitrogen and sired, tungstic acid, ammonium tungstate, hydrogen in combining proportions over it and the like can be reduced directly in the at 600 C. while employing pressure.-

Now what we claim is contact tube 'bymeans of the mixture of i 1. The process of producmg ammoma, by

nitrogen'and hydrogen, provided the abovenamed temperature of 600 C..be not conreducing a tungsten compound with a gas siderably exceeded and the catalytic produccontaining hydrogen at a moderate temperation of ammonia can be immediately proture so as to obtain a tungsten which posceeded with. If desired, the tungsten can sesses at least one hundred times the catabe precipitated or placed on carriers, such lytic power of zinc and then passing a curfor instance as silica and asbestos. rent of nitrogen and hydrogen at a tempera- Example 3: Pass a current of hydrogen at and continues. Any tungsten-nitrogen comture of from about 550 to about 600 0., substantially as hereinbefore described.

2. The process of producing ammonia, by reducing a tungsten compound with a gas containing hydrogenwrt a moderate temperature so as to obtain a tungsten which possesses at least one hundred times the catalytic power of zinc and then passing a current of nitrogen 'and hydrogen under pressure over such tungsten at a temperature of from about 550 to about 600 (1,.

while "employing a temperature of from about 550 to about 600 C.

4:. The process of producing ammonia by reducing-an oxy-compound of tungsten with hydrogeiiat a temperature not considerably exceeding- 600 6., and tlien passing a cure rent of nitrogen and hydrogen under pressure over the tungsten thus obtained while employing a temperature of from about 550 to about600 (J.

5. The process of producing ammonia by reducing an oxyscompound of tungsten with hydrogen under pressure at atemperature not considerably exceeding 000 (1, and then passinga current of nitrogen and hydrogen under pressure over the tungsten thus produced While employing a temperature of from about 550 to about 600 L).

In testimony whereof we have hereunto set our hands in the presence of two subscribing Witnesses.

DR. FRITZ HABER, CARL BOSCH. ALXVIN MITTASCH.

Witnesses to signature 1:

VVoLnEMAR HAUPT, "HENRY HASPER. Witnesses to signatures 2 and 3:

A. O. TITTMANN, J. ALEo. LLOYD. 

